Soybean contracts on the CBOT were down because of profit booking by the investors ahead of the annual USDA conference. The most active May futures on the CBOT was down 0.3% at $10.4225 a bushel. The annual USDA conference will release acreage estimates for upcoming US crop planting at its two-day meeting. Profit booking was also seen in the contract after it hit an 11-month high of $10.50 per bushel due to concern over hot and dry weather in Argentina which may hit the output there.